The red star marks the epicentre of the Glenuig magnitude 3.5 ML event of 06:02, 23 January 2011.

Seismograms of the Glenuig earthquake of 23 January 2011 as recorded on the BGS KPL and PGB broadband seismometers.
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Date

23 January 2011

Origin time

06:02 49.0s UTC

Lat/Lon

56.822° North / 5.784° West

Grid ref

169.1 kmE / 776.4 kmN

Depth

16.2 km

Magnitude

3.5 ML

Locality

22 km WSW of Glenfinnan

Intensity

4 EMS

BGS have detected an earthquake at 06:02 UTC on 23 January 2011 located approximately
22 km west-north-west of Glenfinnan, Highland. Many people throughout the region have reported having
felt this event.

An earthquake of this size and depth might be felt up to 80–120 km away. Please tell us if you felt the earthquake at BGS Earthquakes.

This is the largest earthquake detected in the general area since the magnitude 3.5 ML event on 10 January 2008 near Glenfinnan. Historically, the largest earthquakes to have occurred nearby were the magnitude 3.6 Moidart event that occurred on 14 October 1902 and the magnitude 3.2 Moidart event of 1 February 1809.

BGS have received several reports from Skye, Mull, Inverness and Oban of a felt event at around 06:00 UTC.

'It's not particularly unusual to get eight earthquakes in 30 days even in the UK.

Most of the events listed on our website (www.earthquakes.bgs.ac.uk) are small and many of them would not have been felt. However, it is a little bit unusual to get three magnitude 3.5+ earthquakes in just a little over 30 days.

We usually get a magnitude 3.5 earthquake somewhere in the UK roughly every 12–18 months. This average is based on recordings of earthquake activity in the UK over the past 40 years as well as our historical catalogue.

However, earthquakes can also behave in a more random way that sometimes results in clusters in a short period of time as well as intervals without any earthquakes.

We tend to only notice the clusters and not the periods of quiet.

In more active parts of the world three such earthquakes in a short period of time wouldn't be at all unusual.'

Dr Brian Baptie, Head of Seismology at the British Geological Survey.

Earthquake frequency

Magnitude

UK earthquake frequency

5

1 every 20 years

4

1 every 3–4 years

3

3 each year

2

25 each year

1

100s each year

The UK is likely to experience one magnitude 5 earthquake every 20 years. Smaller earthquakes are more frequent.